01 - Combine chicken pieces with yogurt, lemon juice, ginger paste, garlic paste, garam masala, cumin, turmeric, chili powder, and salt in a large bowl. Mix thoroughly to coat evenly. Cover and refrigerate for at least 1 hour, or overnight for maximum flavor penetration.
02 - Set Instant Pot to Sauté mode. Add 2 tablespoons butter and allow to melt. Add diced onion, minced garlic, and ginger paste. Sauté until onions become translucent and soft, approximately 3-4 minutes.
03 - Pour in tomato puree and add ground cumin, smoked paprika, ground coriander, and cayenne pepper. Stir constantly and cook for 2 minutes to allow spices to bloom and flavors to develop.
04 - Add the marinated chicken along with all remaining marinade liquid into the pot. Stir thoroughly to incorporate chicken with the sauce base.
05 - Secure the lid and ensure steam valve is sealed. Select Manual or Pressure Cook setting on High for 8 minutes.
06 - Allow natural pressure release for 10 minutes once cooking cycle completes. Then carefully quick-release any remaining pressure before opening the lid.
07 - Switch back to Sauté mode. Pour in heavy cream and add remaining 2 tablespoons butter. Simmer for 2-3 minutes while stirring continuously until sauce thickens and becomes velvety. Season with salt to taste.
08 - Serve immediately over basmati rice or with warm naan bread. Sprinkle generously with chopped fresh cilantro as finishing touch.